A swim-in-place spa, also referred to as a swim-in-place pool, is sometimes used in areas where there is insufficient space to install a swimming pool or simply used to provide uninterrupted swimming to a user in a limited body of water. Such spa comprises a current creating device. The device uses a swim-in-place jet to produce a jet directed toward a swimmer. The jet is configured such that the forces on the swimmer balance. The swimmer thereby swims but stays substantially immobile relative to the spa.
In most cases, the device requires a plurality of swim-in-place jets to generate a sufficient mass flow rate to balance a thrust generated by a swimmer. The plurality of jets thus creates a non-uniform velocity profile in the swim-in-place spa. Hence, different portions of a swimmer's body experiment different forces and the water surface is turbulent. The waves on the water surface impair the swim quality compared to a traditional swimming pool.